Liquid feeding system



Dec. 5, 1950 J. L. RAY

LIQUID FEEDING SYSTEM Filed July 13, 1946 all/ 924a? v INVENTOR lovvvwoi, 9%1/3 ATTORNEY Patented Dec. 5, 1950 His-Chalmers Man f ct r h pMilwaukee, Wis, a corporation of Delaware Application: July I3, 1946,Serial No. 683,356

, 9 "Claims,

This invention relates to liquid feeding systems and the principalobject of: the invention is the provision of newand improved systems ofthis un -1 V a Another objrectlof the. invention is theprovision of, aliquid feeding system which continuity of iiquid'feed ismaintained and,more particularly, to a system comprising more. than. 01 pump means andin which continuity of liquid-feed is maintainedwhen'one of the-pumpmeans fails,

Another object of the. invention is the pro vision of a liquid feedingsystem in which an auxili-arypump means-is; caused to take the pumpingload in response to failure of. the primary pumping means.

Another object of the invention is the provision 'of a, liquid. feedingsystem in which an auxiliary pump means is inmotion and in readiness totake. over the pumping load but unde normal conditions does: anegligible amount of work; and hence is; not subject tov the usual weardue to operation, nor subject to bre-a-kages: of the parts of the pumpmeans. or its driving means, or failure of its driving means, and ingeneral not subject to any conditions which are more likely to: causefailure of any kind when the pump means is under full, load.

Another object of the invention is the attainment of the foregoing'objects with maximum simplicitm maximum certainty and a minimum ofparts;

Other objects will appear as the description "of the invention proceeds.

The novel features of the invention andhow the objects are attained willappear from this specification I and the accompanying drawing showingone embodiment of the invention and forming a part of this. application,and all these novel features are intended to be pointed out in theclaims.

In the drawings-g Fig. 1 is a principally diagrammatic. View, cerpain ofthe parts being in section, of a system em hpdying the invention, theparts Being in the posilti'on they assume when the system is in normalhperation; and

Fig. 2 is a View similar to 1 but with the parts in the position theyassume when the primary pump means has failed.

Referring first more particularly to Fig. 1, a i h i' pump mean is ihere hown as having its discharge outlet ll connected by a conduit i2,th u imm r ion f3 f d sch r e q i u The i d be fuel and the discharge 2conduit I4 may lead to any apparatus inwhich the fuel is burned, but theliquid mayhe liquid other than fuel and be fed to any apparatus orplace; where the liquid is utilized or disposed oi in any way. 7

auxiliary pump means. I5 has its discharge outlet I6 connected to theinlet ll of the primary pump means It. As here shown this connectioncomprises a conduit I8 connected, through a connection 19, to a conduit20' which is in turn connected, through a connection 2l-, to a conduit22 connected to the inlet, l -lof the primary pump means I0. Liquid mayflow from a source of liquid here shown as a tank 23, through a conduit24, through a: connection 25, to a conduit 26 connected to the inlet 21of the auxiliary pump means I5.

The pump means In and [5 are preferably driven from. separate shafts,and the primary pump means Iii has a somewhat greater capacity than theauxiliary pump means l5. Preferably the pump means H1 and I5 are of thepositive displacement type;

Bypass conduit means is provided around the m ry P p means Ill, thisbypass comprising a conduit 2 78 connected to the connection I9 at oneend to the inlet 29 of a check valve 30-. The outlet 31 of. the checkvalve has connected thereto one end of a conduit 32, the other end ofwhich is connected to the connection I3. The check valve '39 is hereshown as comprising a valve seat 33 with which a ball '34 is cooperable.The ball 34 may be biased to the seat 33 by a spring 3 5. The checkvalve 30 is constructed and arranged to prevent flow therethrough if thepressure at its outlet 3! is higher than at its inlet 2 9, and to permitflow therethrough when the pressure at its inlet 29 is greater than atits out let 3 'l-. Any form of check valve for performing thesefunctions is suitable,

Bypass conduit means is also provided around the auxiliary pump means[5, this bypasscomprising a conduit 36 connected at one end to theconnection 25 and at the other end to the inlet 3'! of a check valve 38.The outlet 39 of the check valve 38 has connected thereto an end of aconduit B0, the other end of which is connected to the connection 2 I.The check valve 38 is neife shown as comprising a valve seat 4| withwhich a hall 42 is cooperable. The ball 42 may be. biased to the seat byaspring 43. The check valve 38 is constructed and arranged to preventflow thf ea through if the pressure at its outlet 39 is h at its inlet31 and, to permit new therethrough when the pressure at its inlet '31 isgreater than its outlet 39. Any form of check valve for performing thesefunctions is suitable.

If desired, conduit means 44 connected to the discharge conduit at oneend and leading to the tank 23 at the other, may be provided, a springloaded valve 45 being interposed. The valve 45 is here shown ascomprising a ball 46 pressed to a seat 41 by a spring 48. The spring 48may be adjusted so that the ball 46 will not leave the seat 41 unlessthe pressure in the discharge conduit means I4 rises to a predeterminedvalue in excess of a desired pressure in the conduit means. When thevalve 45 opens, excess liquid flows back into the tank 23.

The operation of the system is as follows. Referring first to Fig. 1, inwhich the arrow indi cate the flow of liquid and the direction of flow,and assuming that the primary pump means it has the capacity ofdelivering 100 units of liquid flow to the discharge conduit means H! atthe desired line pressure, and that the auxiliary pump means l5 has thecapacity of delivering 90 units of liquid flow, it will be evident that.since the pump means Hi and I5 are connected in series by means of theconduits i8, 26 and 22, the auxiliary pump means 55 will deliver theliquid discharged thereby to the suction or inlet side of the primarypump means ill. The auxiliary pump means 55 draws then 90 units of liuid from the tank 23 through the conduits 24, 25, these 90 units beingdischarged into the conduit [8, thence into the conduit 29. The primarypump means iii draws an additional 0 units of liquid from the conduit24, into the conduit 35, thence through the check valve 38, through theconduit 40 into the conduit 22. The check valve 38 opens by reason ofthe negative pressure produced by the primary pump means in the conduit22. Thus there are 100 'units of liquid flow in the conduit 22 and these100 units are delivered to the discharge conduit I4. The check valve 33is closed by reason of the higher liquid pressure in the conduit 32 thanin the conduit 28, and hence flow is prevented in the bypass around theprimary pump means Hi. It will be evident that under the hereinbeforedescribed conditions, illustrated by Fig. 1, the auxiliary pump meansdoes a negligible amount of work.

Referring now to Fig. 2, this indicates the primary pump means Ill as ot Of operation. the auxiliary pump means l5 continuing in operation. Theliquid flow is then as indicated by the arrows. The auxiliary pump meansI 5 now draws 9!) units of liquid through the conduits 24, 26,discharging it through the conduit l8, through the now open check valve30, into the conduit 32 and thence into the discharge conduit 4 at fullline pressure. The check valve 38 orens and the check valve 38 closesbecause the primary pump means H3 is producing no difference in pressureas between the conduits I2, 22. The check valve 30 freely opens due tothe pressure produced by the auxiliary pump means l5, and of course thecheck valve 38 prevents any flow from the auxiliary pump means I5 to theconduit 36.

The assumption that the ratio of capacities of the larger pump means tothe smaller pump means is as one hundred to ninety was made merely forconvenience in describing the operation, it being understood that thisratio may be made any other suitable value, either small or larger;

From the foregoing it will be apparent to those skilled in the art thatthe illustrated embodiment of the invention provides a new and improvedliquid feeding system and accordingly accomplishes the objects of theinvention. On the other hand, it will also be obvious to those skilledin the art that the illustrated embodiment of the invention may bevariously changed and modified, or features thereof singly orcollectively, embodied in other combinations than those illustratedwithout departing from the spirit of the invention, or sacrificing allof the advantages thereof, and that, accordingly, the disclosedembodiment is illustrative only, and the invention is not limitedthereto.

It is claimed and desired to secure by Letters Patent:

1. A liquid feeding system, comprising: discharge conduit means; atleast two pump means; conduit means for connecting said pump means inseries to feed liquid to said discharge conduit means; bypass conduitmeans around a first of said pump means; check valve means, interposedin said bypass conduit means, so constructed and arranged that itprevents flow therethrough from the discharge side of said first pumpmeans and permits flow in the opposite direction; second bypass conduitmeans around the second of said :pump means; and check valve means,interposed in said second bypass conduit means, so constructed andarranged that it permits flow therethrough to the inlet side of saidfirst pump means and prevents flow in the opposite direction.

2. A liquid feeding system, comprising: discharge conduit means; atleast two pump means of different capacities for feeding liquid to saiddischarge conduit means; means for so connecting said pump means thatwhen both of said pump means are in operation a negligible part of thework in feeding liquid to said discharge conduit means is done by one ofsaid pump means; and means so constructed and arranged that upon failureof the other of said pump means all of the work done in feeding liquidto said discharge means is done by said one of said pump means.

3. A li uid feeding system, comprising: discharge conduit means; atleast two pump means, one of said pump means being of smaller capacitythan the other; means for s0 connecting said pump means that when bothsaid pump means are in operation a negli ible part of the work infeeding li uid to said discharge conduit means is done by said pumpmeans of smaller capacity; and means so constructed and arranged thatupon failure of the larger of said pump means all of the work done infeeding li uid to said discharge conduit means is done by said pumpmeans of smaller capacity.

4. A liquid feeding system, comprising: dischar e conduit means; atleast two pump means; conduit means for connecting said pump means inseries to feed liquid to said discharge conduit means, a first of saidpump means being of larger capacity than the se-"on'd of said pumnmeans, said second pump m ans being connected to discharge to the inletof said first pump means: and means so constructed and arranged thatupon failure of said first pump means said second pump means isconnected to discharge directly to said discharge crnduit means.

5. A liquid feeding system, comprising: discharge conduit means: atleast two pump means; conduit means for connecting said pum means inseries to feed'liquid to said discharge conduit means, a first of s idpump means being of larger capacity than the second of said pump means,

second pump means being connected to discharge to the inlet of saidfirst pump means; bypass conduit means around said first pump means;check valve means, interposed in said bypass conduit means, soconstructed and arranged that it prevents flow therethrough from thedischarge side of said first pump means and permits flow in the oppositedirection; second by pass conduit means around said second pump means;and check valve means, interposed in said second bypass conduit means,so constructed and arranged that it permits flow therethrough to theinlet side of said first pump means and prevents flow in the oppositedirection.

6. A liquid feeding system, comprising: discharge conduit means; atleast two pump means; conduit means for connecting said pump means inseries to feed liquid to said discharge conduit means, a first of saidpump means being of larger capacity than the second of said pump means,said second pump means being connected to discharge to the inlet of saidfirst pump means; conduit means for providing a bypass around said firstof said pump means; check valve means, interposed in said bypass conduitmeans, so constructed and arranged that it is normally closed and opensin response to fluid pressure generated by the other of said pump meanswhen said first pump means fails.

'7. A liquid feeding system, comprising: discharge conduit means; atleast two pump means, one of said pump means being of smaller capacitythan the other; means for connecting the pump means of smaller capacityto discharge to the inlet of the pump means of larger capacity so thatwhen both said pump means are in operation a negligible part of the workin feeding liquid to said discharge conduit means is done by said pumpmeans of smaller capacity; and means so constructed and arranged thatupon failure of the larger of said pump means all of the work done infeeding liquid to said discharge conduit means is done by said pumpmeans of smaller capacity.

8. A liquid feeding system, comprising: discharge conduit means; atleast two pump means of difierent capacities in series for feedingliquid from a source to said discharge conduit means; means for soconnecting said pump means that when both of said pump means are inoperation 6 i a minor part of the work in feeding liquid to saiddischarge conduit means is done by one of said pump means, saidconnecting means including bypass conduit means from the source to apoint between said pump means, and check valve means biased to closedposition, interposed in said bypass conduit means and so constructed andarranged that when both of said pump means are in operation said checkvalve is open; and means so constructed and arranged that upon failureof the other of said pump means said one of said pump means is connecteddirectly to said discharge conduit means and all of the work done infeeding liquid to said discharge conduit means is done by said one ofsaid pump means.

9. A liquid feeding system, comprising: discharge conduit means; atleast two pump means in series for feeding liquid from a source to saiddischarge conduit means, a first of said pump means being of largercapacity than the second of said pump means, said second pump meansbeing connected to discharge to the inlet of said first pump means;bypass conduit means from the source to a point between said pump means;check valve means biased to closed positioned, interposed in said bypassconduit means and so constructed and arranged that when both of saidpump means are in operation said check valve is open; and means soconstructed and arranged that upon failure of the larger of said pumpmeans said smaller one of said pump means is connected directly to saiddischarge conduit means.

' JAMES L. RAY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,218,565 Vickers Oct. 22, 19402,366,388 Crosby Jan. 2, 1945 FOREIGN PATENTS Number Country Date216,225 Switzerland 1941 703,569 France 1931

